Conveying lines of this type are known. They are characterised by the fact that each drive for the conveying line is realised via drive shafts which drive driving rollers with chain drives. The kinetic energy necessary for the drive is usually provided by a motor. The conveying line has here at least one driving roller driven by a drive shaft, which drives at least a portion, respectively a section, of the conveying line. For that purpose it is known to drive the drive shaft with a chain drive. According to the state of the art the drive shaft has a toothed wheel for that over which a chain drives the conveying line. It is also known to drive simultaneously several drive shafts via a chain.
The problem of this type of drives of conveying lines is that the conveying lines are blocked at times because of machining cycles in such a way that the blocking devices are turned into the conveying line in order to block the conveyed good. The result is that the chain and the toothed wheel are, of course, stressed more than usual. As the driving chains have a considerable length the result is further that, if for example several drive shafts are driven by one chain, the chain is stressed also differently. By means of stress of the chains by a concussion or an impact the life of the chains is reduced considerably.
Therefore it is, for example, necessary that, if the chain is stretched more than 3%, it has to be replaced. This happens usually with a suitable load after several years. Often the life of the chain of the conveying line is significantly shorter than the life of the production installation in which the conveying line is integrated. It may be possible to compensate this slow lengthening of the chain by regular removing chain links, however, the chain has to be replaced if correspondingly stretched more than 3%, as the interaction between chain and toothed wheel cannot be guaranteed anymore. The removal of individual chain links as well as the replacement of the entire chain is very expensive for corresponding conveying lines which extend over a larger distance.